LTE uses Orthogonal Frequency-Division Multiplexing (OFDM) in the DL (downlink) and discrete-Fourier-Transform-Spread OFDM (DFTS-OFDM) in the UL (uplink). The two different link directions use different transmissions schemes or frequency-division multiple access (FDM) technologies. In general, DL and UL are quite different in LTE, which is shorthand for Long-Term Evolution, a 3GPP telecommunications standard. In the standardization of the 5th-Generation (5G) standard known as NR, or “New Radio,” it is currently discussed to include both OFDM and DFTS-OFDM in the UL. Using different FDMs may lead to issues in particular regarding reference signals.